Marine Polysaccharides in Microencapsulation and Application to Aquaculture: “From Sea to Sea”

This review’s main objective is to discuss some physico-chemical features of polysaccharides as intrinsic determinants for the supramolecular structures that can efficiently provide encapsulation of drugs and other biological entities. Thus, the general characteristics of some basic polysaccharides are outlined in terms of their conformational, dynamic and thermodynamic properties. The analysis of some polysaccharide gelling properties is also provided, including the peculiarity of the charged polysaccharides. Then, the way the basic physical chemistry of polymer self-assembly is made in practice through the laboratory methods is highlighted. A description of the several literature procedures used to influence molecular interactions into the macroscopic goal of the encapsulation is given with an attempt at classification. Finally, a practical case study of specific interest, the use of marine polysaccharide matrices for encapsulation of vaccines in aquaculture, is reported

Editorial of virtual special issue Frontiers in Water Biophysics 2017

The present virtual special issue (VSI) of the Journal of Molecular Liquids contains the proceedings of the 4th Conference on Frontiers in Water Biophysics (FWB2017) held in Erice, Sicily (Italy) from 23 to 27 May 2017 at the Ettore Majorana Foundation and Centre for Scientific Culture, in the frame of the V Course of the International School of Sta- tistical Physics (Directors: P. Hanggi, F. Marchesoni)

Conformational features of galacturonans. II. Configurational statistics of pectic polymers

2nonenoneJ. Ruggiero;R. Urbani;A. CesaroJ., Ruggiero; Urbani, Ranieri; Cesaro, Attili

Chitosan nanoparticles: preparation, size evolution and stability

PURPOSE: Characterisation of chitosan-tripolyphosphate nanoparticles is presented with the aim of correlating particle shape and morphology, size distribution, surface chemistry, and production automatisation with preparation procedure, chitosan molecular weight and loaded protein. METHODS: Nanoparticles were prepared by adding drop wise a tripolyphosphate-pentasodium solution to chitosan solutions under stirring. Trehalose, mannitol and polyethylene-glycol as bioprotectants were used to prevent particle aggregation and to reduce mechanical stress during freezing and drying processes. RESULTS: As a novel result, time evolution of the particle size distribution curve showed the presence of a bimodal population composed of a fraction of small particles and of a second fraction of larger particles attributed to the rearrangement of particles after the addition of tripolyphosphate. Storage for 4 weeks resulted in a slight increase in average size, due to the continuous rearrangement of small particles. Improvement of nanoparticle stability after lyophilisation and spray-drying was observed in the presence of all bioprotectants. Trehalose was the best protectant for both methods. Finally, in vivo tests using chick embryos assessed the biocompatibility of chitosan, tripolyphosphate and the nanoparticles. CONCLUSION: The simple ionotropic gelation method with low-MW chitosan was effective in achieving reproducible nanoparticles with the desired physico-chemical and safety characteristics

Stacking and Branching in Self-Aggregation of Caffeine in Aqueous Solution: From the Supramolecular to Atomic Scale Clustering

The dynamical and structural properties of caffeine solutions at the solubility limit have been investigated as a function of temperature by means of MD simulations, static and dynamic light scattering, and small angle neutron scattering experiments. A clear picture unambiguously supported by both experiment and simulation emerges: caffeine self-aggregation promotes the formation of two distinct types of clusters: linear aggregates of stacked molecules, formed by 2–14 caffeine molecules depending on the thermodynamic conditions and disordered branched aggregates with a size in the range 1000–3000 {AA}. While the first type of association is well-known to occur under room temperature conditions for both caffeine and other purine systems, such as nucleotides, the presence of the supramolecular aggregates has not been reported previously. MD simulations indicate that branched structures are formed by caffeine molecules in a T-shaped arrangement. An increase of the solubility limit (higher temperature but also h..